Odd Roar Schmidt

30.05.2018

Technologial Frontiers of Power Conversion.

31 May 2018Slide 1

Eltek A/S

31 May 2018Slide 2

World leader in DC power to telecom world wide.

• Approx. 15% of the market WW

• Approx. 25% of the market WW with Delta, which bought Eltek in 2016

• Renevue approx. 4,4Billion NOK in 2017

• 2500 employes WW.

• Head office in Drammenwith approx 200 employes.

• R&D PowerElectronics, Controlller,SW, embedded SW

• Product Management

• QA

• Industrialisation

• Innovation

• Operations

Eltek A/S

31 May 2018Slide 3

The key drivers for this sucsess is;

• Designed for lowest cost

• Designed for highest reliability.

• Designed for highest efficiency.

How to achieve the key drivers

• Very experienced and knowledgeable R&D Eng., which are able to push the

bounderies.

• New Topologies

• New component technologies

• Cooperate with University like NTNU, Virginia Tech, etc

• Cooperate with Semiconductor manufactores like Infinion, Panasonic etc.

• Participate in research program like Powebase, Hippe etc

Eltek A/S

31 May 2018Slide 4

Wide band Gap devices

• SIC MosFet

• Gallium Nitride(GAN) transistors

GaN is the future

Rectifier with GaN

31 May 2018Slide 5

GaN is the future

INCREASING THE EFFICIENCY INCREASING THE POWER DENSITY

IMPROVING THE RELIABILITY REDUCING THE COST

• PFC: Reliable and costefficient totem pole. Low ohmictransistors

• DCDC: Well switching very low ohmic transistors (<40mOhm)

• Syncrec: No paracitics, very low ohmic transistors

• GaN allows increased switching frequency• Smaller inductors and capacitors• Less filtering

• GaN itself will reach price parity with Silicon• GaN allows increased switching frequency• Smaller inductors and capacitors• Less filtering

• No steep breakdown voltage of the device• Behaves more like a ceramic capacitor• Not susceptible to cosmic radiation

GaN

GaN is the future

▪ Eltek is first vendor with mass production of GaN rectifiers▪ Eltek has the most competitive 98% range of rectifiers

5/31/2018 Product Road Map - CONFIDENTIAL!Slide 8

FP2 3kW SuperHEKey specifications

• 3kW versions. 97,8% efficiency, released

• 2kW available 2018, now

• Compatible with 93%, 95%, 96% and 97% rectifiers

• Cost analysis: We are far better than competition

• Using GaN totempole in PFC

• Silicon MosFets in DC/DC

• Telecom specifications (fuse instead of Oringfets, better

EMI, <50% load)

• 10000 rectifier manufactored

• 2000 rectifier in the field in Russia,

Europe, Asia.

• NO FAILURES SO FAR

❑Totempole Boost with GaN

Mosfets

31 May 2018Slide 9

GaN / Totem Pole issues

Figure 1. Totempole with GAN

transistor

PG-DSO-20-87 package

Complexity of GaN / Totem Pole issues

31 May 2018Slide 10

A challenging journey to develop and tune all possible parameters…

Vf Diode

Vthreshold

Isaturation

Topology

Ipk

Idioderms

Add

Negative Vgate

Tuning

deadtime td

Add

Clamp

Shoot

Through

Increase

IgateEfficiency loss

External

Diode

Tuning

Clamp

Main technical issues for the totempole PFC stage

31 May 2018Slide 11

• Gate drive

• Peak Current Limiter

• Dead time control in totempole topology

• Frewheeling diodes in totempole

• Thermal design

Reliability testing

31 May 2018Slide 12

Reliability testing

31 May 2018Slide 13

HTOB testing

• According to IPC9592 revB.

• Duration 1000hours at max ambient , +50degC

• Eltek expanded the test to 2000hour afterrecommendation

• And output power cycling 10 times during thefirst 30min with steady input power

• The GaN PFC stage is stressed at high input voltage, 264Vac and at low input voltage, 200Vac

• Input Power On/off cycle 10times with 1min. On and 1min. Off. See Figure 7

• 30 rectifiers in parallell were tested

• Tests done

• 5 HTOB tests were done before all weaknesseswere discovered and solved

• For the performed testing, 150 rectifiers wereused

• The last HTOB test passed 2000hours, withoutfailures

Figure 7. HTOB testing overview. NB

high AC input voltage done at 264 Vac

Reliability testing

31 May 2018Slide 14

Input power cycling

• On/off cycle 10times with 1min. On

and 1min. Off. Also 10min off, then

turned on

• This is a very good reliability test for

the GaN PFC stage due to the

voltage/current and thermal stress

• At 45degC ambient the input power is

turned on and off, which add thermal

stress to the GaN chip, in particular

after the 10min off period.

• See picture 3 Picture 3 HTOB system in Eltek Slovakia for up to

48rectifier/converters, up to 144kw

Next Infineon/EU projectUltimateGaN

Odd Roar SchmidtEltek15.11.2017

UltimateGaN

31 May 2018Slide 16

UltimateGaN – the project idea

• Objectives: – Best in class power density and efficiency enabled with the newest GaN on Si

Technologies

• Increase of market share of RF and Power applications made in Europe

• Technical Work packages:

• Eltek WP 6

- WP6: GaN RF and Power applications

• Focus on density and effiencieny.

Experience the power.Experience the power.Experience the power.